Polyfluorinated sulfonamides

ABSTRACT

This invention pertains to polyfluorinated sulfonamides having the formula 
     
         C.sub.n F.sub.2n+1 --CH.sub.2 --.sub.b SO.sub.2 --NRR&#39; 
    
     wherein n is a number of from 1 to about 20; b is an integer of from 2 to about 20; R is selected from the group consisting of a hydrogen radical and an alkyl radical having from 1 to about 10 carbon atoms; and R&#39; is selected from the group consisting of a hydrogen radical, an alkyl radical of from 1 to about 10 carbon atoms, a cyclic alkyl radical of from 5 to 12 carbon atoms, and an aryl radical of from about 6 to 12 carbon atoms. These compounds are prepared through the action of polyfluorinated sulfonic chloride on an amino derivative.

This is a continuation of application Ser. No. 466,051 filed May 1,1974, abandoned, which in turn is a continuation of application Ser. No.5,352, filed Jan. 23, 1970, now abandoned.

SUMMARY OF THE INVENTION

This invention relates to the field of industrial sulfonamides. Briefly,these compounds have found extensive usage as auxiliary ingredients inthe formulation of products useful in the textile, leather, and paperindustries. For example, these compounds serve as surface active agentsand as leveling agents for use in waxes, greases, varnishes and paints.It has been found that the polyfluorinated sulfonamides of the presentinvention are especially suited to these uses.

Briefly stated, the present invention relates to polyfluorinatedsulfonamide compounds and the method of their preparation. The compoundsof this invention have the structure

    C.sub.n F.sub.2n+1 --CH.sub.2 --.sub.b SO.sub.2 --NRR'

in which:

(a) C_(n) F_(2n+1) corresponds to a straight or branched polyfluorinatedcarbon chain, n being a number of from 1 to 20;

(b) b is an integer of from 2 to 20, and preferably equal to 2 or 4;

(c) R is a radical selected from the group consisting of hydrogen andalkyl radicals containing from about 1 to 10 carbon atoms;

(d) R' is a radical selected from the group consisting of (1) hydrogen,(2) alkyl radicals containing from about 1 to 10 carbon atoms, (3)cyclic alkyl radicals containing from about 5 to 12 carbon atoms, and(4) substituted and non-substituted aryl radicals containing from about6 to 12 carbon atoms; and

(e) the group NRR' can consist of a cyclic amine radical containing from4 to 8 carbon atoms, for example the pyrrolidine radical ##STR1##

These new and useful compounds are prepared by reacting apolyfluorinated sulfonic acid halide with ammonia, a primary amine, or asecondary amine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The reaction proceeds according to the equation ##EQU1##

The temperature range best suited for the reaction is from about 1° to150° C. Usually the reaction is exothermic and external heat is notrequired. In this case it is preferable to begin the reaction at ambienttemperature. However, in some instances the reaction is not appreciablyexothermic (for instance when HNRR' is aniline) or thepolyfluorosulfonylchloride [C_(n) F_(2n+1--CH) ₂ --_(b) SO₂ Cl] is notcompletely soluble in a solvent, and a means of heating the reactionmixture may be resorted to.

It is preferable to use a solvent, but this is not indispensable. Thesolvent must be inert with regard to the reagents involved. Suchsolvents which are suitable include ethers such as ethyl ether,isopropyl ether, tetrahydrofuran; esters such as ethyl acetate, ethylformate; halogenated hydrocarbons such as chloroform, carbontetrachloride, methylene chloride, trichloro-1,1,2-trifluoroethane, andother solvents which satisfy the requirement of inertness stated supra.

The ratio of the reagents in mol of HNRR' per mol of C_(n) F_(2n+1)--CH₂ --_(b) SO₂ Cl is preferably at least equal to 2 in order toneutralize the hydrochloric acid liberated during the reaction.

The following examples are provided to further point out and describevarious embodiments of the present invention. These examples are notintended to limit the invention in any way.

EXAMPLE 1

C₂ F₅ --C₂ H₄ --SO₂ Cl (12.3 g; 0.05 mol) was dissolved in ethyl ether(100 cm³) and ammonia was added gradually to the solution, whilestirring, at the rate of 7.1 l per hour for 2 hours. At the beginning ofthe addition of ammonia, a white solid substance was immediately formed.During the first 15 minutes the temperature increased from 20° to 35° C.and remained at 35° C. for 1 hour before gradually receding to 25° C.When the reaction was complete, the reaction medium was washed in three100 ml. portions of water. The ethereal portion was then dried withanhydrous sodium sulfate which was removed by filtration beforeevaporating the ethyl ether. In this manner 11.7 g of solid matter wasobtained, which upon recrystallization from 100 cm³ of a mixture ofcarbon tetrachloride (95% by volume) and ethyl acetate yielded 10.3 g ofC₂ F₅ --C₂ H₄ --SO₂ NH₂.

This sulfonamide was obtained in a yield of 90.5%.

EXAMPLE 2

34.6 g of C₄ F₉ --C₂ H₄ --SO₂ Cl was dissolved in 100 cm³ of ethyl etherand ammonia (15 l/h) was added to the solution, while stirring for aperiod of 2 hours. At the beginning of the addition of ammonia, a whitesolid substance was immediately formed. In the course of the first 10minutes of adding ammonia, the temperature rose from 20° to 34° C., andit remained at 34° C. for 45 minutes before dropping gradually to 25° C.When the reaction was finished, ethyl ether (200 cm³) was added to thereacting medium and the resulting solution was washed successively inthree 100 ml. portions of water. The ethereal portion was then dried onanhydrous sodium sulfate, which was removed by filtration before theevaporation of ethyl ether. In this manner 32.8 g of solid matter wasobtained, which upon recrystallization in 50 cm³ of a mixture of carbontetrachloride (90% by volume) and ethyl acetate, gave 30.1 g of C₄ F₉--C₂ H₄ --SO₂ --NH₂ having a melting point of 47°-49° C. The yield was92%.

EXAMPLE 3

50 g of C₆ F₁₃ --C₂ H₄ --SO₂ Cl was dissolved in 100 cm³ of ethyl ether,and ammonia (7 l/h) was added to the solution, while stirring for aperiod of 2 hours. Immediately on the addition of ammonia, a white,solid substance formed. During the first 15 minutes of adding ammonia,the temperature rose from 20° to 35° C. and it remained at 35° C. for 1hour before gradually dropping to 25° C. When the reaction was finished,the procedure of Example 1 was followed and 43 g of a solid substancehaving a melting point of 90°-93° C. was obtained. This solid matter wasrecrystallized in 150 cm³ of a mixture of carbon tetrachloride (90% byvolume) and ethyl acetate and 39.1 g of C₆ F₁₃ --C₂ H₄ --SO₂ --NH₂having a melting point of 92°-93° C. was recovered.

The yield was 81.5%.

EXAMPLE 4

44.6 g of C₆ F₁₃ --C₂ H₄ --SO₂ Cl was dissolved in 200 cm³ of ethylether and 17.5 g of methylamine was added while stirring over a periodof 2.5 hours. Immediately upon the addition of methylamine, a solid wasformed. The temperature rose from 25° C. to 34° C. in 30 minutes andstabilized at this temperature for 45 minutes before dropping graduallyto 25° C. When the reaction was finished, the reacting medium was washedsuccessively in three 200 cc portions of water. The ethereal solutionwas dried on anhydrous sodium sulfate which was separated by filtration.Evaporation of the ether yielded 42.3 g of solid matter, which wasrecrystallized in 150 cm³ of a mixture of carbon tetrachloride (90% byvolume) and ethyl acetate. 41.5 g of C₆ F₁₃ --C₂ H₄ --SO₂ --NH--CH₃having a melting point of 80°-81° C. was obtained.

The yield amounted to 94%.

EXAMPLE 5

22.3 g of C₆ F₁₃ --C₂ H₄ --SO₂ Cl was dissolved in 100 cm³ of ethylether and to the constantly stirred solution was added 9.8 g of anilineover a period of 30 minutes. Immediately after the addition of aniline,a white, solid substance was formed. The reacting medium was heated to35° C. for 1.5 hours. When the reaction was finished the procedure ofExample 1 was followed and 24.7 g of solid matter was obtained which wasrecrystallized in 50 cm³ of carbon tetrachloride. 23.4 g of ##STR2##having a melting point of 64°-66° C. was isolated.

The yield was 93%.

EXAMPLE 6

22.3 g of C₆ F₁₃ --C₂ H₄ --SO₂ Cl was dissolved in 100 cm³ of ethylether and to the constantly stirred solution was added 10.4 g ofcyclohexylamine over a period of 30 minutes. At the outset, a solid,white substance was formed. The temperature rose from 20° to 35° C. andit remained at 35° C. for 30 minutes before dropping gradually to 25° C.after 2 hours. When the reaction was finished, the procedure of Example1 was followed and 24.4 g of solid matter was isolated uponrecrystallization in 150 cm³ of hexane 23.9 g of ##STR3## having amelting point of 66°-68° C. was recovered.

The yield attained 94%.

EXAMPLE 7

22.3 g of C₆ F₁₃ --C₂ H₄ --SO₂ Cl was dissolved in 100 cm³ of ethylether and to the constantly stirred solution was added 7.5 g ofpyrrolidine for a period of 30 minutes. Immediately upon the addition ofpyrrolidine, a white, solid substance formed. The temperature rose from20° C. to 34° C. in 15 minutes and stabilized at this temperature for 20minutes and then dropped gradually to 23° C. after 2 hours. When thereaction was finished, 500 cm³ of ethyl ether was added and the solutionwhich resulted was washed successively with two 100 cm³ portions ofwater. After drying and evaporating as in Example 1, 23.1 g of solidmatter was isolated. This was recrystallized in 200 cm³ of a mixture ofcarbon tetrachloride (90% by volume) and ethyl acetate. 20.6 g of##STR4## having a melting point of 97°-99° C. was obtained.

The yield amounted to 86%.

EXAMPLE 8

22.3 g of C₆ F₁₃ --C₂ H₄ --SO₂ Cl was dissolved in 100 cm³ of ethylether and to the constantly stirred solution was added 717 g ofdiethylamine. Immediately a solid, white substance formed. Thetemperature rose from 20° to 35° C. in 20 minutes and stabilized at thistemperature for 20 minutes and then dropped gradually to 25° C. after 2hours. When the reaction was finished, the procedure of Example 1 wasfollowed and 23.1 g of solid matter was obtained which was thenrecrystallized in 50 cm³ of hexane. 21.9 g of C₆ F₁₃ --C₂ H₄ --SO₂ --N(C₂ H₅)₂ having a melting point of 68°-70° C. was isolated.

The yield was 91%.

EXAMPLE 9

136.5 g of C₈ F₁₇ --C₂ H₄ --SO₂ Cl was added to 500 cm³ of ethyl etherand to the constantly stirred mixture ammonia was added for 4 hours at arate of 15 l/h. The temperature rose from 20° to 34° C. in 20 minutesand stabilized at this temperature for 11/2 hours before droppinggradually to 23° C. The ethyl ether was removed through evaporationleaving a solid substance which was washed successively with two 400 cm³portions of ethyl acetate. After filtration the filtrate was recoveredand concentrated to 250 cm³. Then 250 cm³ of carbon tetrachloride wasadded, resulting in recrystallization of C₈ F₁₇ --C₂ H₄ --SO₂ --NH₂.117.5 g of C₈ F₁₇ --C₂ H₄ --SO₂ --NH₂ having a melting point of143°-146° C. was recovered.

The yield was 89%.

EXAMPLE 10

27.3 g of C₈ F₁₇ --C₂ H₄ --SO₂ cl was dissolved in 100 cm³ of ethylether and over a period of 2 hours 8.5 g of methylamine was added to theconstantly stirred solution. A solid, white substance formed as soon asthe methylamine was introduced. The temperature rose from 20° to 34° C.in 20 minutes and stabilized at this temperature for 45 minutes beforegradually dropping to 25° C. Ethyl ether was then removed by evaporationand a solid substance was obtained which was extracted with 200 cm³ ofethyl acetate. The extraction solution was filtered and the ethylacetate evaporated yielding 25.2 g of solid matter which wasrecrystallized in 100 cm³ of a mixture of carbon tetrachloride (90% byvolume) and ethyl acetate. 23.2 g of C₈ F₁₇ --C₂ H₄ --SO₂ --NH--CH₃having a melting point of 107° -109° C. were recovered.

The yield amounted to 86%.

EXAMPLE 11

32.3 g of C₁₀ F₂₁ --C₂ H₄ --SO₂ Cl was added to 100 cm³ of ethyl etherand to the constantly stirred mixture 7.5 l/h ammonia was added over aperiod of 2 hours. The temperature rose from 20° to 34° C. in 20 minutesand stabilized at this temperature for 20 minutes before graduallydropping to 23° C. Ethyl ether was removed by evaporation leaving asolid substance which was stirred with 300 cm³ of ethyl acetate. Afterfiltration, a filtrate was recovered and concentrated to a volume of 60cm³. Filtration yielded 26.8 g of solid matter which was recrystallizedin 200 cm³ of a mixture of carbon tetrachloride (50% by volume) andethyl acetate. In this manner 25.4 g of C₁₀ F₂₁ --C₂ H₄ --SO₂ --NH₂having a melting point of 173°-175° C. was recovered.

This sulfonamide was obtained with a yield of 81%.

EXAMPLE 12

18.7 g of C₄ F₉ --C₂ H₄ --₂ SO₂ Cl was dissolved in 100 cm³ of ethylether and to the constantly stirred solution was added ammonia for 2hours at a rate of 7.5 l/h. Immediately upon addition of the ammonia, awhite, solid substance formed. The temperature rose from 20° to 84° C.in 30 minutes and stabilized at this temperature for 80 minutes beforedropping gradually to 22° C. At this point 100 cm³ of ethyl ether wasadded and the resulting mixture was washed in water (four times with 25cm³). The ethereal portion was then dried on anhydrous sodium sulfateand filtered whereupon the ethyl ether was evaporated. In this way, 17.1g of solid matter was obtained which was recrystallized in 110 cm³ ofcarbon tetrachloride. 14.6 g of C₄ F₉ --C₂ H₄ --₂ SO₂ --NH₂ wasisolated, having a melting point of 80°-82° C.

This sulfonamide was obtained with a yield of 82%.

EXAMPLE 13

114.8 g of C₆ F₁₃ --C₂ H₄ --₂ SO₂ Cl was dissolved in 500 cm³ of ethylacetate and to the constantly stirred solution was added ammonia for 4hours at a rate of 15 l/h. White solid matter formed immediately onintroducing ammonia. The temperature rose from 20° to 35° C. in 30minutes and stabilized at this temperature for 11/2 hours beforedropping gradually to 22° C. After the reaction the mixture was washedin water (4 times with 100 cm³) and dried on anhydous sodium sulfate, itwas filtered and the solvent was evaporated. The solid matter recoveredwas recrystallized in 280 cm³ of a mixture of carbon tetrachloride (90%by volume) and ethyl acetate. In this manner, 97.3 g of C₆ F₁₃ --C₂ H₄--₂ SO₂ --NH₂ was isolated.

A yield of 88% was obtained.

EXAMPLE 14

28.7 g of C₈ F₁₇ --C₂ H₄ --₂ SO₂ Cl was dissolved in 200 cm³ of ethylacetate and to the constantly stirred solution ammonia was added for 2hours at a rate of 7 l/h. The temperature rose from 20° to 34° C. in 15minutes and was maintained at this value for 1.5 hours by cooling thereactor by means of a water bath. When the reaction was finished 100 cm³of water was added to the reacting medium. This resulted in a phaseseparation, one phase being a liquid phase, the other a dense gelatinousphase.

The gelatinous phase was extracted 3 times with 100 cm³ portions ofethyl acetate and these extracts were collected with the liquid phasementioned. The resulting solution was dried on anhydrous sodium sulfateand, after filtration, concentrated to 60 cm³. After filtration, 23.1 gof solid C₈ F₁₇ --C₂ H₄ --₂ SO₂ --NH₂ having a melting point of125°-127° C. was obtained.

This sulfonamide was isolated with a yield of 83%.

EXAMPLE 15

27.3 g of C₈ F₁₇ --C₂ H₄ --SO₂ Cl was dissolved in 200 cm³ of ethylacetate and to the constantly stirred solution was added ammonia for 2hours at a rate of 12 l/h. The reaction being exothermic, thetemperature rose from 20° to 40° C. in 30 minutes and then droppedgradually. The reacting medium was then washed 4 times with 50 cm³portions of water and the organic extracts dried on anhydrous sodiumsulfate which was removed by filtration before evaporating the ethylacetate in vacuum. In this way 25.5 g of solid matter was obtained whichwas recrystallized in 200 cm³ of a mixture of carbon tetrachloride (80%by volume) and ethyl acetate. 22.1 g of C₈ F₁₇ --C₂ H₄ --SO₂ --NH₂ wasisolated having a melting point of 143°-146° C.

The yield was 84%.

EXAMPLE 16

22.3 g of C₆ F₁₃ --C₂ H₄ --SO₂ Cl was dissolved in 100 cm³ of chloroformand to the constantly stirred solution was added ammonia for 2 hours ata rate of 12 l/h. The temperature rose from 22° to 41° C. in 30 minutesand then dropped gradually. 100 cm³ of ethyl acetate was then added tothe reacting medium and the resulting mixture washed 4 times with 50 cm³portions of water. The organic extracts were dried on anhydrous sodiumsulfate which was later removed by filtration and the filtrateevaporated. In this manner 21.1 g of solid matter was recovered andrecrystallized in 100 cm³ of a mixture of carbon tetrachloride (90% byvolume) and ethyl acetate. 17.3 g of C₆ F₁₃ --C₂ H₄ --SO₂ --NH₂ wasisolated having a melting point of 92°-93° C.

This sulfonamide was obtained with a yield of 81%.

The preparation of polyfluorinated sulfonic chlorides based on oxidationof the chlorine from a polyfluorinated sulfocyanide C_(n) F_(2n+1)(--CH₂ --)_(b) SCN was described in copending U.S. application Ser. No.851,081 filed Aug. 18, 1969, assigned to the same assignee of thisapplication. The oxidation of a polyfluorinated sulfocyanide having theformula

    C.sub.n F.sub.2n+1 (--CH.sub.2 --).sub.b SCN

by chlorine or bromine is easily carried out when the sulfocyanide isdissolved in a suitable solvent as a reaction medium. It is preferred touse as a solvent a water-acetic acid mixture containing between 5 and25% of the water by volume.

A reaction temperature between about 15° C. and 120° C., can generallybe used, but it is preferred to use a reaction temperature between 15°C. and 75° C.

EXAMPLE I

Chlorine was bubbled to 20° for 3 h at the rate of 4 l/h through amixture of C₂ F₅ --C₂ H₄ --SCN (20.5 g; 0.1 mole) glacial acetic acid(100 cm³) and water (12 cm³ at 20° C.) for 3 hours at the rate of 4l/hour. After 1 hour and 45 minutes, the temperature rose to 61° C. in15 minutes. It remained at this value for 15 minutes and then itgradually went down to the ambient temperature. The chlorine output wasthen stopped and the apparatus purged with a nitrogen flow for 30minutes. A solid (4.1 g) was then filtered from the reaction mixture,the main constituent of which was ammonium chloride. The filtrate wasdistilled and 4 fractions and one residue were obtained as follows:

a--Fraction 54°-60°/100 mm, 58.1 g was composed of water and acetic acid

b--Fraction 62°-5°/100 mm. Water (100 cm³) was added to this fraction,and a dense phase was decanted (7.6 g) composed of water (2.4%), aceticacid (11.6%) and C₂ F₅ --C₂ H₄ --SO₂ Cl (85.8%; 29.6 mole)

c--Fraction 62°-92°/100 mm; 4.8 g was composed of C₂ F₅ --C₂ H₄ --Cl(1%), acetic acid (70%) and C₂ F₅ --C₂ H₄ --SO₂ Cl (29%; 12 mmole)

d--Fraction 92°-7°/100 mm; 6.5 g was composed of C₂ F₅ --C₂ H₄ --Cl(2.8%), C₂ F₅ --C₂ H₄ --SO₂ Cl (92.4%; 24.7 mmole), and threeunidentified compounds (4.8%)

e--Solid residue, 3.2 g unidentified solid. C₂ F₅ --C₂ H₄ --SO₂ Cl wasobtained with a conversion rate of 66.5%

EXAMPLE II

Chlorine at the rate of 4 l/hour was bubbled at 50° C. for 3 hours and30 minutes through a mixture of C₄ F₉ --C₂ H₄ --SCN (30.5 g; 0.1 mole)glacial acetic acid (100 cm³) and water (12 cm³). After 30 minutes, thetemperature rose to 75° C. and remained at this value for 30 minutesbefore gradually going down to the ambient temperature. After stoppingthe chlorine output, the apparatus was purged with a nitrogen flow for30 minutes. A solid (3.9 g) was then filtered from the mixture, the mainconstituent of which was ammonium chloride. The filtrate was distilled;two fractions and one residue were obtained:

a--Fraction 50°-64°/100 mm, constituted of water and acetic acid

b--Fraction 90°-95°/20 mm; 27.4 g composed of C₄ F₉ --C₂ H₄ --1 (3.4%),C₄ F₉ --C₂ H₄ --SCN (12.3%/10 mmole) and C₄ F₉ --C H--SO Cl 84.3%; 23.6mmole)

c--Solid residue 4.6 g unidentified solid C₄ F₉ --C₂ H₄ --SO₂ Cl wasobtained with a conversion rate of 68% and a yield of 75.5%.

The preparation of polyfluorinated sulfocyanides is disclosed in U.S.patent application Ser. No. 795,063 filed Jan. 29, 1969, assigned to thesame assignee of this application.

The perfluoroalkyl sulfocyanides of this invention are prepared byreacting at a temperature in the range between 0° and 250° C., andpreferably between about 40° and 150° C., a perfluoroalkyl halide of theformula

    C.sub.n F.sub.2n+1 (CH.sub.2).sub.a Y

wherein n is an integer from 1 to 20, a is an integer from 2 to 20, andY is a chlorine, iodine or bromine atom, with a sulfocyanide of theformula M(SCN)_(b) wherein M is hydrogen, the ammonium radical or ametal of the group IA, IB, IIA, IIB, or VIII of the periodic table, oraluminum or lead, and b is an integer equal to the valency of M.

Under certain conditions, it is advantageous to carry out the reactionunder pressure. For instance, this will be the case when one or morephysical properties of the solvent or of a reactant, such as its vaporpressure, renders this necessary or advisable. It is also preferred tooperate in the presence of a solvent, but this is not obligatory. Thesolvent must be inert toward the reactants and should have a boilingpoint below approximately 250° C. Suitable solvents include:

I. A primary, secondary, or tertiary alcohol of 1 to 10 carbon atoms,such as ethanol, n-propanol, n-butanol, isopropanol, isobutanol,n-pentanol, isopentanol, n-hexanol, 2-heptanol and n-heptanol;

II. An aliphatic, cyclic, heterocyclic or aromatic ether, such as propyland isopropyl ethers, dioxane, tetrahydrofuran, tetrahydropyrane, andanisole;

III. An aliphatic, cyclic or aromatic ketone, such as 2-butanone,2-pentanone, 3-pentanone, cyclohexanone, and acetophenone;

IV. An aliphatic or aromatic ester such as propyl format methyl acetate,ethyl acetate, phenyl acetate, methyl benzoate, and ethyl benzoate;

V. A tertiary amine, such as trimethylamine, triethylamine, pyridine,2-methylpyridine, and N-methylpiperidine;

VI. An aliphatic or aromatic nitrile, such for instance as acetonitrile,propionitrile, and benzonitrile;

VII. An aromatic hydrocarbon, such as benzene, a xylene, or toluene; and

VIII. A polar aprotic solvent, such for instance as dimethylformamide,dimethylsulfoxide, hexamethylphosphorotriamide, sulfolane, andnitrobenzene.

The following examples, which are not given by way of any limitation,illustrate the new compounds and their preparation pursuant to theinvention of U.S. application Ser. No. 795,063. In all the examples,when a fraction contains several constituents, the mentioned percentagesare molar percentages of the various compounds and the yields arecalculated in relation to the starting fluorinated material.

EXAMPLE III

A mixture of 31 grams of KSCN and 80 cc of ethanol were heated to 78° C.under constant stirring. Then 74.8 grams of C₄ F₉ --C₂ H₄ --I were addedwithin a period of 30 minutes, and when this addition had been achieved,the reaction mixture was kept at 78° C. for three hours. A solidcomprising potassium iodide and unreacted potassium sulfocyanide wasremoved by filtration, and the filtrate was distilled to yield ethylalcohol and two other fractions, to wit,

1. a fraction removed at 40° and /50 mm Hg. This fraction was washedwith water, which yielded an organic phase (11.2 g) comprising C₄ F₉--C₂ H₄ I (88%), C₄ F₉ --C₂ H₄ --SCN (7.4%) and three impurities whichcould not be identified.

2. A fraction removed at 96° and 20 mm Hg, 45 g. This fraction comprisedC₄ F₉ --C₂ H₄ --I (1%), C₄ F₉ --C₂ H₄ --SCN (97.8%) and threenon-identified impurities (1.2%).

The conversion rate and the yield of C₄ F₉ --C₂ H₄ --SCN were about 73and 85%, respectively.

EXAMPLE IV

There was heated to 78° C., with constant stirring, a mixture of KSCN(31 g) and 100 cc of ethanol. To this mixture was added 94.8 g of C₆ F₁₃--C₂ H₄ --I over a period of 11/2 hours, and when this addition had beenmade, the reaction medium was maintained at 78° C. for 41/2 hours. Solidpotassium iodide and unreacted potassium sulfocyanide were filtered off,and the filtrate was distilled to remove the ethyl alcohol and twofractions, to wit,

1. A fraction separated at 80° and 20 mm Hg, weighing 14 g. Thisfraction comprised C₆ F₁₃ --C₂ H₄ --I (78.4%), C₆ F₁₃ --C₂ H₄ --SCN(19.6%), and three non-identified impurities (2%).

2. A fraction separated between 121° and 122° C. at 20 mm Hg andweighing 53.5 g. This fraction contained 132 moles of C₆ F₁₃ --C₂ H₄--SCN. The C₆ F₁₃ --C₂ H₄ --SCN is solid at room temperature and meltsat approximately 35° C.

The conversion rate and the yield of C₆ F₁₃ --C₂ H₄ --SCN is 69 and 79%,respectively.

We claim:
 1. A polyfluorinated sulfonamide compound having the structure

    C.sub.n F.sub.2n+1 --CH.sub.2 --.sub.b SO.sub.2 --NNR'

wherein (a) C_(n) F_(2n+1) corresponds to a straight or branchedpolyfluorinated carbon chain, n being a number of from 1 to 20; (b) b isan integer of from 2 to 20; (c) --NRR' is selected from the group (d) or(e) below: (d) N is nitrogen; R is hydrogen or an alkyl radical of from1 to 10 carbon atoms; and R' is hydrogen, an alkyl radical of from 1 to10 carbon atoms, a cyclic alkyl radical of from 5 to 12 carbon atoms, oran aryl hydrocarbon radical of from 6 to 12 carbon atoms; (e) --NRR' isa pyrrolidine radical having the structure ##STR5##
 2. A polyfluorinatedsulfonamide compound having the structure

    CnF.sub.2n+1 --CH.sub.2 --.sub.b SO.sub.2 --NRR'

wherein (a) C_(n) F_(2n+1) corresponds to a straight or branchedpolyfluorinated carbon chain, n being a number of from 1 to 20; (b) b isequal to 2 or 4; (c) --NRR' is selected from the group (d) or (e) below:(d) N is nitrogen; R is hydrogen or an alkyl radical of from 1 to 10carbon atoms; and R' is hydrogen, an alkyl radical of from 1 to 10carbon atoms, a cyclic alkyl radical of from 5 to 12 carbon atoms, or anaryl hydrocarbon radical of from 6 to 12 carbon atoms; or (e) --NRR' isa pyrrolidine radical having the structure ##STR6##